JP2023517695A - Method and apparatus for video encoding and decoding - Google Patents

Abstract

Different implementations are described, and in particular implementations for video encoding and decoding are presented. Thus, encoding or decoding is to obtain a residual coding mode of a block of a picture, which residual coding mode is normal residual coding mode (RRC) or transform skip residual coding mode (TSRC). and decoding the block of the picture according to the obtained residual coding mode. According to a specific property, the residual coding mode is set to normal residual coding mode (RRC) when transform skip is disabled. According to another particular property, residual coding modes are decoded from syntax elements when transform skip is enabled. [Selection drawing] Fig. 1b

Description

At least one of the present embodiments relates generally to a method or apparatus, e.g., for video encoding or decoding, and more specifically, including obtaining residual coding modes for blocks of a picture, It relates to a method or apparatus.

The domain technical field of one or more implementations is generally related to video compression. At least some embodiments use HEVC (High Efficiency Video Coding) defined in "ITU-T H.265 Telecommunication standards sector of ITU (10/2014), series H: audiovisual and multimedia, systems iovisual services-coding of moving existing video compression systems, such as H.265, which stands for High efficiency video coding, also known as MPEG-H Part 2, and H.265, described in the ITU-T H.265 or compared to developing video compression systems such as VVC (Versatile Video Coding) (JVET, Versatile Video Coding, a new standard under development by the Joint Video Experts Team) Regarding efficiency.

To achieve high compression efficiency, image and video coding schemes typically employ prediction, including motion vector prediction, and transforms to exploit spatial and temporal redundancies in video content. . Intra-prediction or inter-prediction is commonly used to exploit correlation within or between frames, and then the difference between the original image and the predicted image, often called prediction error or prediction residual, is transformed, quantized, , and entropy-encoded. To reconstruct the video, the compressed data is decoded by the inverse process corresponding to entropy coding, quantization, transform and prediction.

Among the tools of the coding tools used within HEVC and VVC, transform skip (TrSkip) allows the encoder to bypass the transform stage if the transform provides no coding benefit. According to one example, bypassing transformations is useful for screen content whose residual statistics do not match the transformation characteristics. According to another example, the transform (and quantization) results in a lossy coding mode, so the transform is also bypassed for lossless coding. Moreover, compared to HEVC, VVC introduced a new mode of coding residuals resulting from transform skipping. That is, the residual coefficients are coded differently for regular blocks and for transform skip blocks. It is desirable to optimize the high-level syntax (HLS) of transform-skip coding for different possible coding modes of content.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome at least one of the drawbacks of the prior art. To this end, according to general aspects of at least one embodiment, a method is presented. The method includes decoding a syntax element indicating whether transform skip data is present in the bitstream and, in response to the presence of transform skip data, associated residual coding modes for blocks of the picture. decoding at least one syntactic data element, wherein the residual coding mode is one of a normal residual coding mode or a transform skip residual coding mode. .

According to another general aspect of at least one embodiment, a method is presented. The method includes encoding a syntax element indicating whether transform skip data is present in the bitstream; encoding at least one syntactic data element, wherein the residual coding mode is one of a normal residual coding mode or a transform skip residual coding mode. .

According to another general aspect of at least one embodiment, an apparatus is presented. The apparatus comprises one or more processors, the one or more processors decoding a syntax element indicating whether transform skip data is present in the bitstream and responsive to the presence of transform skip data. and decoding at least one syntactic data element associated with a residual coding mode of a block of a picture, wherein the residual coding mode is a normal residual coding mode or a transform skip residual. One of the difference coding modes.

According to another general aspect of at least one embodiment, an apparatus is presented. The apparatus comprises one or more processors, the one or more processors encoding a syntax element indicating whether transform skip data is present in the bitstream and responsive to the presence of transform skip data. and encoding at least one syntax data element associated with a residual coding mode of a block of a picture, wherein the residual coding mode is a normal residual coding mode or a transform skip residual. One of the difference coding modes.

According to another general aspect of at least one embodiment, a method is presented for encoding. The encoding method is to obtain the residual coding mode of the blocks of the picture, which is the regular residual coding mode (RRC) or the transform skip residual coding mode (RRC). encoding the blocks of the picture according to the obtained residual coding mode. Obtaining the residual coding mode of the block according to the particular characteristic includes encoding at least one syntactic data element associated with the residual coding mode of the block of the picture when transform skip is enabled. According to another particular characteristic, obtaining the residual coding mode of the block includes setting the residual coding mode to normal residual coding mode (RRC) when transform skip is disabled. Advantageously, normal residual coding mode (RRC) or transform skip residual coding mode (TSRC) are not coded when transform skip is disabled.

According to another general aspect of at least one embodiment, a method for decoding is presented. The decoding method is to obtain a residual coding mode of a block of the picture, where the residual coding mode is one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC). and decoding the block of the picture according to the obtained residual coding mode. Obtaining the residual coding mode of the block according to the particular characteristic includes decoding at least one syntactic data element associated with the residual coding mode of the block of the picture when transform skip is enabled. According to another particular characteristic, obtaining the residual coding mode of the block includes setting the residual coding mode to normal residual coding mode (RRC) when transform skip is disabled. Regarding the coding method, normal residual coding mode (RRC) or transform skip residual coding mode (TSRC) are implicitly decoded when transform skip is disabled.

According to another general aspect of at least one embodiment, an apparatus for encoding is presented comprising means for implementing any one of the encoding method embodiments.

According to another general aspect of at least one embodiment, an apparatus for decoding is presented comprising means for implementing any one of the decoding method embodiments.

According to another general aspect of at least one embodiment, an apparatus for encoding is provided, comprising one or more processors and at least one memory. The one or more processors are configured to implement any one of the encoding method embodiments.

According to another general aspect of at least one embodiment, an apparatus for decoding is provided, comprising one or more processors and at least one memory. The one or more processors are configured to implement any one of the decoding method embodiments.

In accordance with another general aspect of at least one embodiment, the at least one syntactic data element is encoded or decoded, the at least one syntactic data element enabling transform skipping of at least one region of the picture. In that regard, blocks of a picture are coded or decoded according to the obtained residual coding mode when the intra-subpartition split type is set to no_split.

According to another general aspect of at least one embodiment, the at least one syntactic data element is encoded or decoded, and the at least one syntactic data element is an intra sub-partition (ISP) of When enabled and transform skip is enabled, it relates to enabling transform skip for at least one region of a picture. In accordance with another general aspect of at least one embodiment, when intra-subpartitions (ISPs) are enabled and transform skip is enabled, at least one high resolution for enabling transform skip for at least one region of the picture. Level syntax elements are signaled in the Sequence Parameter Set (SPS).

In accordance with another general aspect of at least one embodiment, the at least one syntactic data element is encoded or decoded, the at least one syntactic data element enabling transform skipping of at least one region of the picture. In that regard, blocks of a picture are coded or decoded according to the obtained residual coding mode when transform skip is enabled for ISP and intra-subpartition split type is set to no_split.

In accordance with another general aspect of at least one embodiment, blocks of a picture are subjected to residual coding obtained when transform skip is enabled for ISP and intra subpartitioning type is set to no_split Encoded or decoded according to the mode.

In accordance with another general aspect of at least one embodiment, at least one syntactic data element is encoded or decoded, one syntactic data element for a constraint enabling transform skip coding mode (TRskip), One syntactic data element relates to defining a constraint that enables transform skip residual coding mode (TSRC) when the constraint enables transform skip coding mode (TRskip).

In accordance with another general aspect of at least one embodiment, the at least one syntactic data element is encoded or decoded, the at least one syntactic data element enabling transform skip residual coding mode (TSRC) Regarding defining constraints.

In accordance with another general aspect of at least one embodiment, the at least one syntactic data element is encoded or decoded, the at least one syntactic data element performing transform skip residual coding of at least one region of the picture. With respect to enabling, obtaining the residual coding mode means decoding at least one syntactic data element associated with the residual coding mode for blocks of the picture when transform skip residual coding is enabled. Including further. In accordance with another general aspect of at least one embodiment, at least one syntactic data element associated with enabling transform skip residual coding for at least one region of a picture is signaled in a sequence parameter set (SPS). be done.

According to another general aspect of at least one embodiment, a non-transitory computer-readable medium containing data content generated according to the method or apparatus of any of the preceding descriptions is presented.

According to another general aspect of at least one embodiment, a signal is provided that includes video data generated according to the method or apparatus of any of the preceding descriptions.

One or more of the embodiments also provide a computer-readable storage medium storing instructions for encoding or decoding video data according to any of the methods described above. This embodiment also provides a computer-readable storage medium storing a bitstream generated according to the method described above. This embodiment also provides a method and apparatus for transmitting a bitstream generated according to the method described above. The embodiments also provide a computer program product containing instructions for performing any of the methods described.

In accordance with general aspects of at least one embodiment, an example decoding method is illustrated. Another example of a decoding method is illustrated according to general aspects of at least one embodiment. Another example of a decoding method is illustrated according to general aspects of at least one embodiment. According to general aspects of at least one embodiment, an example encoding method is illustrated. 1 illustrates a block diagram of an embodiment of a video encoder, in which various aspects of an embodiment may be implemented; FIG. 1 illustrates a block diagram of an embodiment of a video decoder, in which various aspects of an embodiment may be implemented; FIG. 1 illustrates a block diagram of an example apparatus in which various aspects of the embodiments may be implemented; FIG.

The drawings and description have been simplified to illustrate elements relevant to a clear understanding of the present principles, and for purposes of clarity, many of the elements found in typical encoding and/or decoding devices have been simplified. It should be understood that other elements are excluded. It will be understood that, although terms such as first and second may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

Various embodiments are described in terms of picture encoding/decoding. They can be applied to encode/decode portions of pictures, such as slices or tiles, or entire sequences of pictures. Moreover, various embodiments are described in terms of decoding blocks (eg, coding units CU) and are easily derived to coding blocks.

Various methods have been described above, each method comprising one or more steps or actions for achieving the described method. The order and/or use of specific steps and/or actions may be modified or combined, unless a specific order of steps or actions is required for proper operation of the method.

First, several embodiments of methods for encoding or decoding pictures are disclosed in accordance with the present principles, followed by additional information and general embodiments implementing the disclosed methods. be.

At least one embodiment for encoding or decoding using a transform skip tool While encoding a picture into a bitstream, the prediction residual or residuals remaining between the original content and its prediction are transformed and Quantized and the quantized coefficients are entropy coded into the bitstream. Transformation removes spatial redundancies and quantization removes irrelevant details. Among the tools of the coding tools used within HEVC and VVC, transform skip (TrSkip) allows the encoder to bypass the transform stage for lossless coding if the transform provides no coding benefit. With respect to screen content coding (SCC), particularly for coding graphics, and more generally for non-camera captured video, block differential pulse coded modulation (BDPCM) is used to reduce residual and its previously coded residual takes advantage of pattern repetition in graphics within the same picture to remove content redundancy. In these modes, Transform Skip/BDPCM Residual Coding (TSRC) enables different residual coding schemes compared to normal residual coding (RRC) mode.

In the latest version of VVC, a slice level flag slice_ts_residual_coding_disabled_flag is introduced to switch between TSRC and RRC in case of TrSkip. That is, a TrSkip coding unit (TrSkip CU) is coded using normal coding mode (RRC) if this flag is set to 1, or if the flag is set to 0. If so, it is either coded using transform skip coding mode (TSRC). This mode advantageously enables a lossless mode with RRC, where TrSkip mode is signaled and RRC is used with a quantization parameter of 4 or less, so that both transform and quantization are bypassed. . Similarly, this mode allows BDPCM CUs to be coded with RRC, whereas previously BDPCM CUs were always coded using TSRC. In the following, high-level signaling for transform skip mode (TrSkip) and block differential pulse coded modulation (BDPCM) in versions of VVC are described. TrSkip and BDPCM are controlled by the SPS flag, where BDPCM is conditioned on activation of TrSkip as described in the table below.

式中、ｌｏｇ２＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｍａｘ＿ｓｉｚｅ＿ｍｉｎｕｓ２は、ＶＶＣのバージョンに説明されているように、変換スキップの最大ブロックサイズを指定し、
Ｌｏｇ２＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｍａｘ＿ｓｉｚｅ＿ｍｉｎｕｓ２は、変換スキップに対して使用される最大ブロックサイズを指定し、０～３の両端を含む範囲内にあるものとする。
変数ＭａｘＴｓＳｉｚｅは、１＜＜（ｌｏｇ２＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｍａｘ＿ｓｉｚｅ＿ｍｉｎｕｓ２＋２）に等しく設定される。
及び、ｍｉｎ＿ｑｐ＿ｐｒｉｍｅ＿ｔｓ＿ｍｉｎｕｓ４は、以下のように、変換スキップ及びパレットモードの場合に最小量子化パラメータを判定する（パレットモードは、画面コンテンツコーディング内で使用されて、限られた数の色の間の色のインデックスを使用してコンテンツをコード化する）。
ｍｉｎ＿ｑｐ＿ｐｒｉｍｅ＿ｔｓ＿ｍｉｎｕｓ４は、次のように、変換スキップモードの最小許容量子化パラメータを指定する。
ＱｐＰｒｉｍｅＴｓＭｉｎ＝４＋ｍｉｎ＿ｑｐ＿ｐｒｉｍｅ＿ｔｓ＿ｍｉｎｕｓ４ （６４）
ｍｉｎ＿ｑｐ＿ｐｒｉｍｅ＿ｔｓ＿ｍｉｎｕｓ４の値は、０～４８の両端を含む範囲内にあるものとする。

where log2_transform_skip_max_size_minus2 specifies the maximum block size for transform skip as described in the version of VVC;
Log2_transform_skip_max_size_minus2 specifies the maximum block size used for transform skip and shall be in the range 0 to 3 inclusive.
The variable MaxTsSize is set equal to 1<<(log2_transform_skip_max_size_minus2+2).
and min_qp_prime_ts_minus4 determines the minimum quantization parameter for transform skip and palette mode (palette mode is used in screen content coding to reduce the number of colors between a limited number of colors), as follows: use the index to encode the content).
min_qp_prime_ts_minus4 specifies the minimum allowable quantization parameter for transform skip mode as follows.
QpPrimeTsMin=4+min_qp_prime_ts_minus4 (64)
The value of min_qp_prime_ts_minus4 shall be in the range 0 to 48 inclusive.

As mentioned above, switching between RRC and TSRC is done within the slice level using the flag slice_ts_residual_coding_disabled_flag.

このフラグが次のように定義される場合、
ｓｐが現在のスライスの場合。０に等しいｓｌｉｃｅ＿ｔｓ＿ｒｅｓｉｄｕａｌ＿ｃｏｄｉｎｇ＿ｄｉｓａｂｌｅｄ＿ｆｌａｇは、ｒｅｓｉｄｕａｌ＿ｔｓ＿ｃｏｄｉｎｇ（）構文構造を使用して、現在のスライスのための変換スキップブロックの残差サンプルを解析することを指定する。ｓｌｉｃｅ＿ｔｓ＿ｒｅｓｉｄｕａｌ＿ｃｏｄｉｎｇ＿ｄｉｓａｂｌｅｄ＿ｆｌａｇが存在しない場合、これは０に等しいと推論される。

If this flag is defined as
If sp is the current slice. slice_ts_residual_coding_disabled_flag equal to 0 specifies that residual samples of transform skip blocks for the current slice are parsed using the residual_ts_coding( ) syntax structure. If slice_ts_residual_coding_disabled_flag is not present, it is inferred to be equal to 0.

Coding of BDPCM is performed at the CU level.

ＲＲＣとＴＳＲＣとの間のＴｒＳｋｉｐ及びスイッチングは、スライスレベルフラグｓｌｉｃｅ＿ｔｓ＿ｒｅｓｉｄｕａｌ＿ｃｏｄｉｎｇ＿ｄｉｓａｂｌｅｄ＿ｆｌａｇを使用して、変換ユニットレベルで行われる。

TrSkip and switching between RRC and TSRC is done at the transform unit level using the slice level flag slice_ts_residual_coding_disabled_flag.

However, this slice level flag slice_ts_residual_coding_disabled_flag created some ambiguity in controlling transform skipping as a tool for bypassing transform and transform skip residual coding, or as an alternative coding method for residuals. In fact, transform skip is controlled by the SPS flag (sps_transform_skip_enabled_flag) and TSRC is controlled at the slice level (slice_ts_residual_coding_disabled_flag). The two flags are coded independently, which gives four possibilities.
1) Both TrSkip and TSRC are activated. This is the default case in VTM common test conditions, the transformation can be bypassed and the subsequent residual coefficients are coded using TSRC,
2) Both TrSkip and TSRC are deactivated. This is the mode in which conversion skip is completely deactivated. In this case no conversion is bypassed and the TSRC is not used.
3) TrSkip is activated and TSRC is deactivated. This is the current method for lossless coding of natural content in VTM. In this case the transform may be skipped, but RRC is used for subsequent residual coefficients.
4) TrSkip is deactivated and TSRC is activated. This is a possible but impractical mode in VVC. In fact, if TrSkip is not enabled, translation is not bypassed and therefore not used regardless of whether TSRC is activated. This is inconsistent with the VVC design and inconsistent signaling should be avoided.

In addition, VVC has some constraint flags to define profiles. For TrSkip, the constraint flag no_transform_skip_constraint_flag is used. If it is set to one, conversion skipping is disabled by the corresponding SPS flag. This corresponds to profiles where transform skipping is not implemented by the decoder. For example, profiling is done via the following constraint flags:

ＴｒＳｋｉｐ制約フラグの意味論は次のとおりである。
１に等しいｎｏ＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、ｓｐｓ＿ｔｒａｎｓｆｒｏｍ＿ｓｋｉｐ＿ｅｎａｂｌｅｄ＿ｆｌａｇが０に等しいことを指定する。０に等しいｎｏ＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、そのような制約を課さない。

The semantics of the TrSkip restriction flag are as follows.
no_transform_skip_constraint_flag equal to 1 specifies that sps_transfrom_skip_enabled_flag is equal to 0. A no_transform_skip_constraint_flag equal to 0 imposes no such constraint.

However, if TrSkip is activated, TSRC is not used but implemented. For example, TrSkip is useful for profiles that support losslessness, but in which case TSRC is not implemented. Efficient implementation of this reversible mode is therefore desirable.

Finally, another tool related to the Transform tool is the Intra Subpartition (ISP), which in the case of the Transform Unit (TU) can be used to generate predictions for the next subpartition. , using a reconstructed sample of each subpartition. In fact, when the ISP is enabled either horizontally or vertically, the CU is divided into 2 or 4 sub-partitions. However, transform skip is not activated in ISP, so ISP mode is not compatible with lossless coding. This limitation is acceptable because TSRC does not fit ISP residuals well for common test conditions, and the cost of signaling two modes (TrSkip or otherwise) seems to outweigh the benefits of TSRC. seems to be However, it is desirable to enable IDP for losslessness in RRC by adoption of slice_ts_residual_coding_disabled_flag.

Therefore, at least one embodiment for encoding or decoding using a transform skip tool advantageously avoids the coding slice_ts_residual_coding_disabled_flag when transform skip is disabled. At least one alternative embodiment for encoding or decoding using the transform skip tool advantageously enables ISP for lossless mode. At least one alternative embodiment for encoding or decoding using a transform skip tool can be encoded with RRC, thus enabling BDPCM regardless of TrSkip. And at least one variant embodiment for encoding or decoding using the transform skip tool adds a constraint flag to enable profiles that allow losslessness without TSRC.

FIG. 1a illustrates an example decoding method in accordance with general aspects of at least one embodiment. In the following, different embodiments of signaling/derived conversion tools and coding modes are described for decoding methods, but the principles should be easily derived for encoding methods by those skilled in the art. Therefore, method 10 for decoding a block (eg, coding unit CU) in a picture includes obtaining a residual coding mode, RC mode, at step 11 . As mentioned above, the residual coding mode is one of normal residual coding mode RRC or transform skip residual coding mode TSRC. RC mode is applied while decoding 16 the blocks of the picture to control the entropy coding of the block residuals. According to a specific property, the residual coding mode is set to normal residual coding mode RRC when transform skip is disabled. This embodiment advantageously avoids the coding slice_ts_residual_coding_disabled_flag when transform skipping is disabled. According to another particular property, when transform skip is enabled, the residual coding mode is decoded from slice_ts_residual_coding_disabled_flag.

FIG. 1b illustrates another example of a decoding method according to general aspects of at least one embodiment. According to a particular feature, in step 12 the method includes decoding an SPS flag that enables or disables a transform skip tool sps_transform_skip_enabled_flag. In step 13, TrSkip is tested using the decoded value of sps_transform_skip_enabled_flag. In some cases, TrSkip is disabled and conversion is not bypassed, so TSRC is not used, so in step 14 the RC mode is set to RRC. In some cases, TrSkip is enabled and the residual coding mode is controlled in step 15 by the decoded value of slice_ts_residual_coding_disabled_flag. Therefore, if TrSkip is disabled at the SPS level, there is no need to code slice_ts_residual_coding_disabled_flag without bypassing translation. In other words, slice_ts_residual_coding_disabled_flag is implicitly decoded when TrSkip is deactivated. Therefore, the VVC specification is amended in the slice header (underlined) as follows.

FIG. 1c illustrates another example of a decoding method according to general aspects of at least one embodiment. This exemplary method is an alternative to step 11 of FIG. 1B for obtaining residual coding modes. According to a particular feature, in step 12 the method includes decoding an SPS flag that enables or disables a transform skip tool sps_transform_skip_enabled_flag (TrSkip), and more specifically, if sps_transform_skip_enabled_flag is: is defined as
sps_transform_skip_enabled_flag equal to 1 specifies that transform_skip_flag may be present in the transform unit syntax. sps_transform_skip_enabled_flag equal to 0 specifies that transform_skip_flag is not present in the transform unit syntax.

In step 13, TrSkip is tested using the decoded value of sps_transform_skip_enabled_flag. In some cases, TrSkip is enabled, which means sps_transform_skip_enabled_flag specifies that transform_skip_flag may be present in the transform unit syntax, slice_ts_residual_coding_disabled_flag is decoded in step 15, and residual coding mode is Decoding led_flag set according to the customized value. Alternatively, the residual coding mode is implicitly derived, eg, set to normal residual coding mode RRC. In other words, slice_ts_residual_coding_disabled_flag is only decoded when TrSkip is activated. Although not expressed, the same principle applies in encoding, slice_ts_residual_coding_disabled_flag is encoded in the bitstream when sps_transform_skip_enabled_flag is set to 1, and transform_skip_flag can be present in the transform unit syntax. specify.

Therefore, according to another specific property, slice_ts_residual_coding_disabled_flag, which controls RRC and TSRC with valid TrSkip, is also used for ISP. Therefore, when the intra-subpartition partitioning type is set to no_split, we decode the blocks of the picture using entropy decoding applied to the residuals of the blocks according to the residual coding mode obtained. This variant embodiment advantageously enables ISP for lossless mode. In fact, TrSkip can be beneficially effective for lossless coding at ISPs that use RRC, since switching between RRC and TSRC is possible. Therefore, the VVC specification is amended in the slice header (underlined) as follows.

According to another particular characteristic, when intra-subpartition (ISP) is enabled, at least one syntactic data element (sps_trskip_isp_enabled_flag) associated with enabling transform skip for at least one region of the picture explicitly Signaled. According to another particular property, the at least one high-level syntax element that enables transform skip in combination with the ISP sps_trskip_isp_enabled_flag is set to a sequence parameter set ( SPS). Therefore, according to this property, additional SPS flags are added to enable the combination of TrSkip and ISP. Following a non-limiting example, this flag can be coded as follows.

及び以下のように、復号化された残差においてｓｌｉｃｅ＿ｔｓ＿ｒｅｓｉｄｕａｌ＿ｃｏｄｉｎｇ＿ｄｉｓａｂｌｅｄ＿ｆｌａｇの組み合わせにおいて使用される。

and used in combination with slice_ts_residual_coding_disabled_flag in the decoded residual as follows:

In other words, the blocks of the picture are in the residual coding mode (i.e., decoded using entropy decoding applied to the block residual according to slice_ts_residual_coding_disabled_flag). Advantageously, when sps_trskip_isp_enabled_flag is set to 0, TrSkip with ISP in RRC is not used.

According to a variant embodiment, ISP-TrSkip combination is possible for both RRC and TSRC. Therefore, the ISP-TrSkip combination is advantageously enabled with SPS flags (e.g. lossless) for certain coding conditions, depending on the content, RRC (for natural content) or TSRC (for screen content) may be used. . As mentioned above, according to this variant embodiment, an additional SPS flag is added to enable the combination of TrSkip and ISP.

復号化フラグは、以下のように使用される。

The decoding flags are used as follows.

According to another embodiment, a constraint flag for TSRC is signaled. Therefore, when defining a profile, at least one syntactic data element associated with a constraint enabling transform skip coding mode (TRskip) is decoded and when the constraint enables transform skip coding mode (TRskip) , at least one syntactic data element associated with defining a constraint to enable transform skip residual coding mode (TSRC) is further decoded. As mentioned above, there is some ambiguity in distinguishing TrSkip as a method for bypassing transforms and TrSkip as a method for residual coding (TSRC). In fact, the current version of VVC does not allow defining profiles that skip transformations without implementing TSRC, but this configuration is available. Advantageously, at least one embodiment adds another constraint flag for controlling TSRC as follows.

追加の制約フラグｎｏ＿ｔｓｒｃ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、以下のように定義される。
１に等しいｎｏ＿ｔｓｒｃ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、ｓｌｉｃｅ＿ｔｓ＿ｒｅｓｉｄｕａｌ＿ｃｏｄｉｎｇ＿ｄｉｓａｂｌｅｄ＿ｆｌａｇが１に等しいものとすることを指定する。０に等しいｎｏ＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、そのような制約を課さない。

The additional constraint flag no_tsrc_constraint_flag is defined as follows.
no_tsrc_constraint_flag equal to 1 specifies that slice_ts_residual_coding_disabled_flag shall be equal to 1. A no_transform_skip_constraint_flag equal to 0 imposes no such constraint.

Advantageously, when the flag no_tsrc_constraint_flag is set to 1, a profile is defined that allows transforms to be skipped and RRC to be used for residual coding. Moreover, when the flag no_tsrc_constraint_flag is set to 1, the TSRC is disabled, but a profile is defined that further allows BDPCM to be enabled.

According to the VVC specification version, the slice level for disabling TSRC is conditioned on the transform skip SPS flag and the quantization type. This is because both dependent quantization and signature data concealment cannot be used in RRC, only TSRC is used. In this version of the VVC specification, the header flags are renamed. According to a non-limiting example, slice header flags use the prefix sh_ and picture header flags use the prefix ph_. Therefore, the following slice_ts_residual_coding_disabled_flag and sh_ts_residual_coding_disabled_flag are used interchangeably. The corresponding specification text is:

That is, when either dependent quantization or sign data hiding is enabled for the current slice (sh_dep_quant_enabled_flag=1 or sh_sign_data_hiding_enabled_flag=1), sh_ts_residual_coding_disabled_flag is not signaled, but is inferred to be 0, because Enable TSRC by default. A problem occurs when transform skip is disabled (sps_transform_skip_enabled_flag=0), which means that transform skip is not used, so TSRC is disabled by default. However, the inference value of sh_ts_residual_coding_disabled_flag remains 0 (TSRC is not disabled), constraint flag no_tsrc_constraint_flag cannot be set to 1, and TSRC is not used. That is, constraint flags cannot represent the actual profile.

At least two variant embodiments are described to solve this problem. A first embodiment involves modifying the speculative role of sh_ts_residual_coding_disabled_flag so that TSRC is disabled when skip translation is disabled. Changes to the spec (highlighted in grey).

sh_ts_residual_coding_disabled_flag equal to 1 specifies that residual samples of transform skip blocks for the current slice are parsed using the residual_coding( ) syntax construct. sh_ts_residual_coding_disabled_flag equal to 0 specifies that residual samples of transform skip blocks for the current slice are parsed using the residual_ts_coding( ) syntax structure. When sh_ts_residual_coding_disabled_flag is not present, this is 0! Inferred to be equal to sps_transform_skip_enabled_flag.

By doing so, when sh_ts_residual_coding_disabled_flag is not signaled, it is inferred to be equal to 1 (no TSRC) when transform skip is disabled (sps_transform_skip_enabled_flag=0), or 0 when transform skip is enabled. It is inferred that there is (TSRC is used).

A second embodiment involves modifying the semantics of the constraint flags. That is, no_tsrc_constraint_flag is set to 1 when either sh_ts_residual_coding_disabled_flag is equal to 1 or sps_transform_skip_enabled_flag is 0. The changes to the specification are as follows.

no_tsrc_constraint_flag equal to 1 specifies that sh_ts_residual_coding_disabled_flag shall be equal to 1 or sps_transform_skip_enabled_flag shall be equal to 0. A no_transform_skip_constraint_flag equal to 0 imposes no such constraint.

According to a variant embodiment of the constraint flag, the SPS level flag controls TSRC-RRC switching. That is, in SPS we can add (underlined):

This flag is inferred to be 0 if not coded. If it is 1, the TSRC is invalid. The same slice level flags are used to control TSRC-RRC switching.

及び、制約フラグは、以下のように設計される。

And the constraint flags are designed as follows.

及びその意味論：
１に等しいｎｏ＿ｔｓｒｃ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、ｓｐｓ＿ｔｓｒｃ＿ｄｉｓａｂｌｅｄ＿ｆｌａｇが１に等しいものとすることを指定する。０に等しいｎｏ＿ｔｒａｎｓｆｏｒｍ＿ｓｋｉｐ＿ｃｏｎｓｔｒａｉｎｔ＿ｆｌａｇは、そのような制約を課さない。

and its semantics:
no_tsrc_constraint_flag equal to 1 specifies that sps_tsrc_disabled_flag shall be equal to 1. A no_transform_skip_constraint_flag equal to 0 imposes no such constraint.

In at least some variations of the above-described embodiments, which may help reduce signaling overhead, this constraint flag (no_tsrc_constraint_flag) may be conditioned on the transform skip constraint flag.

In other words, if we know that translation skip is deactivated by that constraint flag, it is practical to do further signaling via the constraint flag that TSRC is deactivated, since TSRC is not used in this case. isn't it.

For example, in an exemplary use case like VVC, the constraint flag for skip transform is named 'no_transform_skip_constraint_flag' and we can condition 'no_tsrc_constraint_flag' in the following manner.

The semantics of no_tsrc_constraint_flag can be expressed as follows, for example.
no_tsrc_constraint_flag equal to 1 specifies that sps_tsrc_disabled_flag is equal to 1. A no_transform_skip_constraint_flag equal to 0 imposes no such constraint. If not available, the value no_tsrc_constraint_flag shall be inferred to be one.

To adapt this SPS flag to the current VVC specification, the following changes are made (highlighted in strikethrough and grey).

The inference role of sps_tsrc_disabled_flag and sh_ts_residual_coding_disabled_flag shall be as follows.
- When sps_tsrc_disabled_flag is not signaled, it is inferred to be 1, so when translation skipping is disabled, TSRC is disabled and the constraint flag (no_tsrc_constraint_flag) is set correctly.
- When the sh_ts_residual_coding_disabled_flag is not signaled, it is inferred to be equal to 0.

In another embodiment, no_tsrc_constraint_flag equal to 1 indicates that TSRC is not used, dependent quantization and sign data hiding shall be deactivated as they cannot be used in RRC. Therefore, when no_tsrc_constraint_flag is equal to 1, no_dependent_quant_constraint_flag and no_sign_data_hiding shall also be one. Uniquely to the semantics of "no_dependent_quant_constraint_flag and no_sign_data_hiding", the corresponding changes to the specification are:
no_dep_quant_constraint_flag equal to 1 specifies that sps_dep_quant_enabled_flag shall be equal to 0. no_dep_quant_constraint_flag equal to 0 imposes no such constraint. The value of no_dep_quant_constraint_flag shall be equal to 1 when no_tsrc_constraint_flag is equal to 1;
no_sign_data_hiding_constraint_flag equal to 1 specifies that sps_sign_data_hiding_enabled_flag is equal to 0. no_sign_data_hiding_constraint_flag equal to 0 imposes no such constraint. The value of no_sign_data_hiding_constraint_flag shall be equal to 1 when no_tsrc_constraint_flag is equal to 1;

FIG. 2 illustrates an example coding method in accordance with general aspects of at least one embodiment. The above-described embodiments of signaling/derivation transform tools and coding modes are compatible with encoding methods and easily combined to implement various embodiments of encoding methods. Therefore, method 20 for encoding blocks (eg, coding units CUs) within a picture includes obtaining a residual coding mode, RC mode, at step 21 . As mentioned above, the residual coding mode is one of normal residual coding mode RRC or transform skip residual coding mode TSRC. RC mode is applied while coding 22 the blocks of the picture to control the entropy coding of the block residuals. According to a specific property, the residual coding mode defaults to normal residual coding mode RRC when transform skip is disabled. This embodiment advantageously avoids the coding slice_ts_residual_coding_disabled_flag when transform skipping is disabled. According to another particular property, the residual coding mode is either set to normal residual coding mode RRC or, when transform skip is enabled, set to transform skip residual coding mode TSRC. is. Then, when transform skip is enabled, the residual coding mode RRC or TSRC is coded into slice_ts_residual_coding_disabled_flag. Advantageously, the coding flag enables the decoder to perform residual decoding corresponding to the coding method.

Additional Embodiments and Information This application describes various aspects including tools, features, embodiments, models, approaches, and the like. Many of these aspects are described specifically and often in what may sound restrictive, at least to illustrate individual characteristics. However, this is for the purpose of clarity of description and is not intended to limit the applicability or scope of those aspects. In fact, all of the different aspects can be combined and interchanged to provide additional aspects. Further, these aspects can be combined and interchanged with aspects described in previous applications.

The aspects described and contemplated in this application can be implemented in many different forms. 3, 4, and 5 below provide some embodiments, although other embodiments are contemplated, and the discussion of FIGS. 3, 4, and 5 limits the frontage of implementations. not something to do. At least one of the aspects relates generally to video encoding and decoding, and at least one other aspect relates generally to transmitting a generated or encoded bitstream. These and other aspects are directed to a method, apparatus, computer readable storage medium having stored thereon instructions for encoding or decoding video data according to any of the described methods and/or any of the described methods. as a computer-readable storage medium having stored thereon a bitstream generated according to

In this application, the terms "reconstructed" and "decoded" may be used interchangeably, and the terms "pixel" and "sample" are , may be used interchangeably, and the terms "image," "picture," and "frame" may be used interchangeably.

Various methods have been described herein, each method comprising one or more steps or actions for achieving the described method. The order and/or use of specific steps and/or actions may be modified or combined, unless a specific order of steps or actions is required for proper operation of the method.

Various methods and other aspects described in this application can be used to modify modules of video encoder 100 and decoder 200, such as transform modules (125, 250), as shown in FIGS. can be Further, aspects of the present disclosure are not limited to VVC or HEVC, for example, other standards and recommendations, existing or developed in the future, and any such standards and recommendations (VVC and HEVC ) can be applied to extensions of Unless otherwise indicated or technically excluded, the aspects described in this application may be used individually or in combination.

In this application, for example, various numerical values are used for flag values. Specific values are for illustrative purposes, and the described aspects are not limited to these specific values. Names of variables, such as flag names, are also presented for illustrative purposes only.

FIG. 3 illustrates encoder 100 . Although variations of this encoder 100 are envisioned, encoder 100 is described below for purposes of clarity without necessarily describing all possible variations.

Before being encoded, the video sequence undergoes pre-encoding processing (101), e.g. applying a color transform to the input color picture (e.g. RGB4:4:4 to YCbCr4:2:0); or through performing remapping of the input picture components (e.g., using histogram equalization of one of the color components) to obtain a signal distribution that is more resilient to compression. . Metadata may be associated with pre-processing and attached to the bitstream.

In encoder 100, pictures are encoded by encoder elements, as described below. A picture to be encoded is partitioned 102 into units, eg CUs, and processed. Each unit is encoded using either intra or inter mode, for example. When a unit is encoded in intra mode, it performs intra prediction (160). In inter mode, motion estimation (175) and motion compensation (170) are performed. The encoder determines 105 whether one of intra or inter mode should be used to encode the unit, and indicates the intra/inter decision by, for example, a prediction mode flag. A prediction residual is computed, for example, by subtracting 110 the prediction block from the original image block.

The prediction residual is then transformed (125) and quantized (130). The quantized transform coefficients, as well as motion vectors and other syntax elements, are entropy coded (145) to output a bitstream. The encoder can skip the transform and apply quantization directly to the untransformed residual signal. The encoder can bypass both transform and quantization, ie the residual is coded directly without applying a transform or quantization process.

An encoder decodes the encoded blocks to provide references for further prediction. The quantized transform coefficients are inverse quantized (140) and inverse transformed (150) to decode the prediction residual. Combining 155 the decoded prediction residual and the predicted block, the image block is reconstructed. An in-loop filter (165) is applied to the reconstructed picture, performing, for example, deblocking/SAO (Sample Adaptive Offset) filtering to reduce coding artifacts. The filtered image is stored in a reference picture buffer (180).

FIG. 4 illustrates a block diagram of video decoder 200 . In decoder 200, the bitstream is decoded by decoder elements, as described below. Video decoder 200 generally performs a decoding pass that is the inverse of the encoding pass, as described in FIG. Encoder 100 also generally performs video decoding as part of the encoded video data.

In particular, the decoder's input includes a video bitstream, which may be produced by video encoder 100 . The bitstream is first entropy decoded (230) to obtain transform coefficients, motion vectors, and other coded information. The picture division information indicates how the picture is divided. Accordingly, the decoder can split the picture according to the decoded picture splitting information (235). The transform coefficients are inverse quantized (240) and inverse transformed (250) to decode the prediction residual. Combining 255 the decoded prediction residual and the predicted block, the image block is reconstructed. Predicted blocks may be obtained (270) from intra prediction (260) or motion compensated prediction (ie, inter prediction) (275). An in-loop filter (265) is applied to the reconstructed image. The filtered image is stored in a reference picture buffer (280).

The decoded picture is subjected to post-decoding processing (285), e.g. inverse color transform (e.g. YCbCr 4:2:0 to RGB4:4:4 conversion), or pre-encoding processing (101). A reverse remapping can also be performed that performs the reverse of the remapping process performed. Post-decoding processing can use metadata derived in pre-coding processing and signaled in the bitstream.

FIG. 5 illustrates a block diagram of an example system in which various aspects and embodiments may be implemented. System 1000 can be embodied as a device including various components described below and configured to perform one or more of the aspects described in this document. Examples of such devices include, but are not limited to, personal computers, laptop computers, smart phones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected appliances, and servers. A variety of electronic devices are included. Elements of system 1000, alone or in combination, may be embodied in a single integrated circuit (IC), multiple ICs, and/or separate components. For example, in at least one embodiment, the processing elements and encoder/decoder elements of system 1000 are distributed across multiple ICs and/or discrete components. In various embodiments, system 1000 is communicatively coupled to one or more other systems or other electronic devices, eg, via a communication bus or via dedicated input and/or output ports. be done. In various embodiments, system 1000 is configured to implement one or more of the aspects described in this document.

System 1000 includes at least one processor 1010 configured to execute instructions loaded therein, eg, to implement various aspects described in this document. Processor 1010 may include embedded memory, input/output interfaces, and various other circuits known in the art. System 1000 includes at least one memory 1020 (eg, a volatile memory device and/or a non-volatile memory device). System 1000 includes storage device 1040, which can include non-volatile memory and/or volatile memory, including, but not limited to, electrically erasable programmable read-only memory ( Electrically Erasable Programmable Read-Only Memory (EEPROM), Read-Only Memory (ROM), Programmable Read-Only Memory (PROM), Random Access Memory (RAM), Dynamic Random Access Memory (DRAM) ), Static Random Access Memory (SRAM), Flash, magnetic disk drives, and/or optical disk drives. Storage devices 1040 may include, as non-limiting examples, internal storage devices, attached storage devices (including removable and non-removable storage devices), and/or network accessible storage devices.

System 1000 includes, for example, an encoder/decoder module 1030 configured to process data to provide encoded or decoded video, which encoder/decoder module 1030 includes its own processor and memory. be able to. Encoder/decoder module 1030 represents a module that may be included in a device to perform encoding and/or decoding functions. As is known, a device may include one or both of an encoding module and a decoding module. Additionally, encoder/decoder module 1030 can be implemented as a separate element of system 1000 or can be incorporated within processor 1010 as a combination of hardware and software, as known to those skilled in the art.

Program code, which is loaded into processor 1010 or encoder/decoder 1030 to perform various aspects described herein, can be stored in storage device 1040 and then in memory 1020 for execution by processor 1010 . can be loaded into According to various embodiments, one or more of processor 1010, memory 1020, storage device 1040, and encoder/decoder module 1030 may perform one or more of various items during execution of the processes stored in this document. can be stored. Such stored items include, but are not limited to, input video, decoded video, or portions of decoded video, bitstreams, matrices, variables, and intermediates from the processing of equations, formulas, operations, and operational logic. It can contain results or final results.

In some embodiments, memory internal to processor 1010 and/or encoder/decoder module 1030 is used to store instructions and to provide working memory for processing required during encoding or decoding. I will provide a. However, in other embodiments, memory external to the processing device (the processing device can be, for example, either processor 1010 or encoder/decoder module 1030) is used for one or more of these functions. used. External memory may be memory 1020 and/or storage device 1040, such as dynamic volatile memory and/or non-volatile flash memory. In some embodiments, external non-volatile flash memory is used to store, for example, the television's operating system. In at least one embodiment, the fast external dynamic volatile memory such as RAM is MPEG-2 (MPEG is also known as Moving Picture Experts Group; MPEG-2 is also known as ISO/IEC 13818; 13818-1 is Also known as H.222, 13818-2 is also known as H.262), HEVC (HEVC is called High Efficiency Video Coding, also known as H.265 and MPEG-H Part 2) , or as working memory for video encoding and decoding operations such as VVC (Versatile Video Coding, a new standard under development by JVET).

Input to the elements of system 1000 can be provided through various input devices, as indicated at block 1130 . Such input devices may include (i) a radio frequency (RF) portion that receives, for example, an RF signal transmitted by a broadcaster, (ii) a component (COMP) input terminal (or COMP input). (iii) Universal Serial Bus (USB) input terminals; and/or (iv) High Definition Multimedia Interface (HDMI) input terminals. not. Other examples, not shown in FIG. 5, include synthetic video.

In various embodiments, the input devices of block 1130 have associated respective input processing elements, as is known in the art. For example, the RF portion can (i) select a desired frequency (also referred to as selecting a signal or bandlimiting a signal to a band of frequencies) and (ii) transforming the selected signal into (iii) bandlimiting again to a narrower band of frequencies to select a signal frequency band that may (for example) be referred to as a channel in certain embodiments; (iv) the downconverted , demodulating the bandlimited signal, (v) performing error correction, and (vi) demultiplexing to select the desired stream of data packets. can be The RF portion of various embodiments includes one or more elements that perform these functions, such as frequency selectors, signal selectors, band limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. including. The RF portion can include tuners that perform a variety of these functions, including, for example, downconverting the received signal to a lower frequency (e.g., intermediate frequency or near-baseband frequency) or to baseband. . In one embodiment of the set-top box, the RF portion and its associated input processing elements receive RF signals transmitted over a wired (e.g., cable) medium, filter, down-convert, and Perform frequency selection by refiltering. Various embodiments rearrange the order of the above-described (and other) elements, remove some of these elements, and/or add other elements that perform similar or different functions. . Adding elements may include inserting elements between existing elements, such as, for example, inserting amplifiers and analog-to-digital converters. In various embodiments, the RF portion includes an antenna.

Additionally, the USB and/or HDMI terminals can include respective interface processors for connecting the system 1000 to other electronic devices over the USB and/or HDMI connections. It should be appreciated that various aspects of input processing, such as Reed-Solomon error correction, for example, may be implemented in separate input processing ICs or implemented within processor 1010, as desired. Similarly, aspects of USB or HDMI interface processing may be implemented in separate interface ICs or within processor 1010, as desired. The demodulated, error corrected and demultiplexed stream is, for example, an encoder/decoder operating in conjunction with processor 1010 and memory and storage elements to process the data stream required for presentation on an output device. provided to various processing elements, including 1030;

The various elements of system 1000 may be provided within an integrated housing, within which the various elements may be provided with suitable connection arrangements, such as an Inter-IC (I2C) bus, wiring, and printing. The circuit boards are interconnected using internal buses known in the art to allow data to be transmitted between them.

System 1000 includes communication interface 1050 that allows communication with other devices over communication channel 1060 . Communication interface 1050 can include, but is not limited to, a transceiver configured to transmit and receive data over communication channel 1060 . Communication interface 1050 may include, but is not limited to, a modem or network card, and communication channel 1060 may be implemented in wired and/or wireless media, for example.

Data is, in various embodiments, streamed to system 1000 using a Wi-Fi network, for example, a wireless network such as IEEE 802.11 (IEEE stands for the Institute of Electrical and Electronics Engineers); or otherwise provided. Wi-Fi signals in these embodiments are received via communication channel 1060 and communication interface 1050 adapted for Wi-Fi communications. Communication channel 1060 in these embodiments is typically connected to an access point or router that provides access to external networks, including the Internet, to enable streaming applications and other over-the-top communications. In other embodiments, streaming data is provided to system 1000 using a set-top box that delivers data over an HDMI connection at input block 1130 . In still other embodiments, the RF connection of input block 1130 is used to provide streaming data to system 1000 . As indicated above, various embodiments provide data in a non-streaming manner. In addition, various embodiments use wireless networks other than Wi-Fi, such as cellular networks or Bluetooth networks.

System 1000 can provide output signals to various output devices including display 1100 , speakers 1110 and other peripheral devices 1120 . The display 1100 of various embodiments includes, for example, one or more of a touch screen display, an organic light-emitting diode (OLED) display, a curved display, and/or a foldable display. Display 1100 may be for a television, tablet, laptop, cell phone (mobile phone), or other device. The display 1100 may also be integrated with other components (eg, like a smart phone) or separate (eg, an external monitor for a laptop). Other peripheral devices 1120 include, in various example embodiments, a standalone digital video disc (or digital versatile disc) (DVR, an abbreviation for both terms), a disc player, a stereo system, and/or One or more of the lighting systems are included. Various embodiments employ one or more peripheral devices 1120 that provide functionality based on the output of system 1000 . For example, a disc player performs the function of playing the output of system 1000 .

In various embodiments, control signals may be transmitted between system 1000 and display 1100, speaker 1110, or other peripheral device 1120 via AV. Communicated using signaling such as Link, Consumer Electronics Control (CEC), or other communication protocols that allow control between devices with or without user intervention. Output devices can be communicatively coupled to system 1000 via dedicated connections through respective interfaces 1070, 1080, and 1090. FIG. Alternatively, output devices can be connected to system 1000 using communication channel 1060 via communication interface 1050 . Display 1100 and speakers 1110 may be integrated into a single unit with other components of system 1000 in an electronic device such as a television, for example. In various embodiments, display interface 1070 includes a display driver, such as a timing controller (T Con) chip.

For example, if the RF portion of input 1130 is part of a separate set top box, display 1100 and speaker 1110 may alternatively be separate from one or more of the other components. In various embodiments where the display 1100 and speakers 1110 are external components, output signals can be provided via dedicated output connections including, for example, HDMI ports, USB ports, or COMP outputs.

Embodiments can be performed by computer software implemented by processor 1010, by hardware, or by a combination of hardware and software. As a non-limiting example, embodiments may be implemented by one or more integrated circuits. Memory 1020 can be of any type suitable for the technical environment, including, but not limited to, optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory. can be implemented using any suitable data storage technology. Processor 1010 can be of any type suitable for the technical environment, including, as non-limiting examples, one or more of microprocessors, general purpose computers, special purpose computers, and processors based on multi-core architectures. can do.

Various implementations include decoding. As used in this application, "decoding" can encompass all or part of a process performed on a received encoded sequence to produce a final output suitable for display, for example. In various embodiments, such processes include one or more of the processes typically performed by decoders, such as entropy decoding, inverse quantization, inverse transform, and differential decoding. In various embodiments, such a process may also or alternatively be a decoder of various implementations described in this application, e.g. It includes a process performed by decoding blocks of a picture according to a residual coding mode set to difference coding mode (RRC).

As a further example, in one embodiment "decoding" refers only to entropy decoding, in another embodiment "decoding" refers only to differential decoding, and in another embodiment "decoding" refers to entropy decoding only. Refers to a combination of decoding and differential decoding. Whether the phrase "decoding process" is intended to refer specifically to a subset of operations or to the broader decoding process generally depends on the context of the particular description. and are considered well understood by those skilled in the art.

Various implementations involve encoding. Similar to the discussion above regarding "decoding", "encoding" as used in this application is performed on an input video sequence to produce, for example, an encoded bitstream. can include all or part of the process In various embodiments, such processes include one or more of the processes typically performed by encoders such as, for example, segmentation, differential encoding, transforms, quantization, and entropy encoding. In various embodiments, such a process may also or alternatively be applied to decoders of various implementations described in this application, e.g., transform skip disabled and residual coding mode encoding skipped. When the residual coding mode is set to normal residual coding mode (RRC), the process is performed by coding blocks of the picture according to the residual coding mode.

As a further example, in one embodiment "encoding" refers only to entropy encoding, in another embodiment "encoding" refers only to differential encoding, and in another embodiment " "Encoding" refers to a combination of differential encoding and entropy encoding. Whether the phrase "encoding process" is intended to refer specifically to a subset of operations or to the broader encoding process generally depends on the context of the particular description. and are considered well understood by those skilled in the art.

It should be noted that the syntactical elements used herein are terms of description. Therefore, they do not preclude the use of other syntactic element names.

When a figure is presented as a flow chart, it should be understood that the figure also provides a block diagram of the corresponding device. Similarly, where a figure is presented as a block diagram, it should be understood that the figure also provides a flowchart of the corresponding method/process.

Implementations and aspects described herein can be implemented in, for example, a method or process, apparatus, software program, data stream, or signal. Even if only considered in the context of a single form of implementation (e.g., only as a method), the discussed feature implementations may also be implemented in other forms (e.g., devices or programs). be able to. An apparatus can be implemented in suitable hardware, software, and firmware, for example. The method may be implemented with a processor, which generally refers to a processing device including, for example, a computer, microprocessor, integrated circuit, or programmable logic device. Processors also include communication devices such as, for example, computers, cell phones, portable/personal digital assistants (“PDAs”), and other devices that facilitate communication of information between end-users.

References to "one embodiment" or "an embodiment" or "one implementation" or "implementation" and other variations thereof refer to the specific features, structures, characteristics, etc. described in connection with the embodiment. is meant to be included in at least one embodiment. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" or "in an implementation" or "in an implementation" appearing in various places in this specification, as well as any other variations, They are not necessarily all referring to the same embodiment.

Additionally, this application may refer to "determining" various information. Determining the information may include, for example, one or more of estimating the information, calculating the information, predicting the information, or retrieving the information from memory.

Further, this application may refer to "accessing" various information. Accessing information includes, for example, receiving information, retrieving information (e.g., from memory), storing information, moving information, copying information, computing information , determining information, predicting information, or estimating information.

Additionally, this application may refer to "receiving" various information. Receiving, like "accessing," is intended to be a broad term. Receiving the information may, for example, include one or more of accessing the information or retrieving the information (eg, from memory). Further, "receiving" typically includes, for example, storing information, processing information, transmitting information, moving information, copying information, erasing information, computing information, Participate in some way during an operation such as determining information, predicting information, or estimating information.

For example, for "A/B", "A and/or B" and "at least one of A and B", the following "/ ', 'and/or', and 'at least one of' selects only the first listed option (A), or It should be understood that selection of only the second listed option (B) or selection of both options (A and B) are intended to be covered. As further examples, "A, B, and/or C" and "at least one of A, B, and C)", such expression means selection of the first listed option (A) only, or selection of the second listed option (B) only, or selection of the third listed option (C) or only the first and second listed alternatives (A and B), or only the first and third listed alternatives (A and C), or the second and third is intended to encompass selection of only the listed options (B and C) or selection of all three options (A and B and C). This can be extended by the number of items listed, as will be apparent to those skilled in this and related arts.

Also, as used herein, the term "signaling" means indicating something specifically to a corresponding decoder. For example, in certain embodiments, an encoder signals a particular one of multiple parameters for matrix-based intra-prediction. Thus, in embodiments, the same parameters are used on both the encoder and decoder sides. Thus, for example, the encoder can send specific parameters to the decoder (explicit signaling) so that the decoder can use the same specific parameters. Conversely, if the decoder already has that particular parameter and other parameters, signaling without transmission (implicit signaling) simply allows the decoder to recognize and select that particular parameter. can be used. By avoiding sending any real function, a bit savings is realized in various embodiments. It should be appreciated that signaling may be accomplished in various manners. For example, one or more syntax elements, flags, etc. are used in various embodiments to signal information to corresponding decoders. Although the above relates to the verb form of the word "signal", the word "signal" can also be used as a noun herein.

This disclosure has described various information such as, for example, syntax that can be transmitted or stored. This information can be packaged or arranged in a variety of ways, such as placing the information in SPS, PPS, NAL units, headers (e.g., NAL unit headers, or slice headers), or SEI messages, according to video standards. Including the common style in Other formats are available, including formats common in system-level or application-level standards, such as placing information in one or more of the following.
SDP (session description protocol), e.g. for session announcements and session invites, as described in RFCs and used in conjunction with RTP (Real-time Transport Protocol) transmissions. a format for describing multimedia communication sessions for the purpose of
A DASH MPD (Media Presentation Description) descriptor, e.g., as used in DASH and transmitted over HTTP, descriptors are associated with an expression or set of expressions,
- RTP header extensions, e.g., as used during RTP streaming;
- ISO base media files, such as those used in OMAF, which in some specifications use boxes, which are object-oriented building blocks defined by a unique type identifier and length, also known as "atoms" format (ISO Base Media File Format),
- HLS (HTTP Live Streaming) manifests sent over HTTP. A manifest can be associated with a version or set of versions of content, for example, to provide characteristics of the version or set of versions.

Implementations can generate a variety of signals formatted to carry information that can be stored or transmitted, for example, as will be apparent to those skilled in the art. Information can include, for example, instructions for performing a method, or data produced by one of the described implementations. For example, the signal can be formatted to carry the bitstream of the described embodiment. Such signals may, for example, be formatted as electromagnetic waves (eg, using the radio frequency portion of the spectrum) or as baseband signals. Formatting can include, for example, encoding the data stream and modulating a carrier with the encoded data stream. The information that the signal carries may be, for example, analog information or digital information. Signals can be transmitted over a variety of different wired or wireless links, as is known. The signal can be stored on a processor readable medium.

A number of embodiments have been described. These features of embodiments may be provided singly or in any combination across various claim categories and types. Further, embodiments may include one or more of the following features, devices, or aspects, singly or in combination, across various claim categories and types.
- Modifying the coding/decoding of a block of a picture of a video, wherein when the block is coded/decoded according to the residual coding mode and transform skip is disabled, the residual coding mode is normal is set to the residual coding mode (RRC) of
- modifying the coding/decoding of blocks of a picture of a video, wherein the blocks are coded/decoded according to a residual coding mode and when conversion skip is enabled, the residual coding of the blocks of the picture; at least one syntactic data element associated with the mode is encoded/decoded, modifying;
- modifying the encoding/decoding of blocks of pictures of a video that combine residual coding modes with intra subpartitions;
When intra-subpartition (ISP) is enabled and transform skip is enabled, inserting in the signaling at least one syntactic data element associated with enabling transform skip for at least one region of the picture. ,
- inserting into the signaling at least one syntactic data element associated with defining a constraint that enables a transform skip residual coding mode (TSRC) by inserting into the signaling;
- A bitstream or signal containing one or more of the described syntax elements or variations thereof.
- A bitstream or signal containing syntax carrying information generated according to any of the described embodiments.
• Enabling the decoder to insert within signaling syntax elements that handle TRSkip and residual coding modes in a manner corresponding to that used by the encoder.
- creating and/or transmitting and/or receiving and/or decoding bitstreams or signals containing one or more of the described syntax elements or variations thereof;
- creating and/or transmitting and/or receiving and/or decoding according to any of the described embodiments;
- A method, process, apparatus, medium for storing instructions, medium for storing data, or a signal according to any of the described embodiments.
• A television, set-top box, mobile phone, tablet, or other electronic device that performs transform skipping and residual coding according to any of the described embodiments.
- Televisions, set-tops that perform transform skipping and residual coding according to any of the described embodiments and display the resulting image (e.g., using a monitor, screen, or other type of display) box, mobile phone, tablet, or other electronic device.
- a television that selects a channel (e.g., using a tuner) to receive the signal containing the encoded image, and performs transform skipping and residual coding according to any of the described embodiments; A set-top box, mobile phone, tablet, or other electronic device.
- Televisions, set-top boxes that receive signals over the air (e.g., using an antenna) containing images encoded according to any of the described embodiments, and perform transform skipping and residual coding. , mobile phone, tablet, or other electronic device.

Claims (21)

a method,
decoding a syntax element (TRskip) indicating whether transform skip data is present in the bitstream;
decoding at least one syntactic data element associated with a residual coding mode of a block of a picture in response to the presence of transform skip data, wherein the residual coding mode is normal residual A method that is one of coding mode (RRC) or transform skip residual coding mode (TSRC). An apparatus comprising one or more processors, the one or more processors comprising:
decoding a syntax element (TRskip) indicating whether transform skip data is present in the bitstream;
and decoding at least one syntactic data element associated with a residual coding mode of a block of a picture in response to the presence of transform skip data, said residual coding mode. is one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC). a method,
encoding a syntax element (TRskip) indicating whether transform skip data is present in the bitstream;
encoding at least one syntactic data element associated with a residual coding mode of a block of a picture in response to the presence of transform skip data, wherein the residual coding mode is normal residual A method that is one of coding mode (RRC) or transform skip residual coding mode (TSRC). An apparatus comprising one or more processors, the one or more processors comprising:
encoding a syntax element (TRskip) indicating whether transform skip data is present in the bitstream;
and encoding at least one syntactic data element associated with a residual coding mode of a block of a picture in response to the presence of transform skip data, wherein said residual coding mode. is one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC). A method for decrypting,
obtaining a residual coding mode of a block of a picture, the residual coding mode being one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC); to obtain;
decoding the block of the picture according to the obtained residual coding mode;
obtaining the residual coding mode of the block comprises decoding at least one syntactic data element associated with the residual coding mode of the block of a picture, provided that transform skip is enabled. . An apparatus for decoding, comprising one or more processors, said one or more processors comprising:
obtaining a residual coding mode of a block of a picture, the residual coding mode being one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC); to obtain;
decoding the block of the picture according to the obtained residual coding mode;
obtaining the residual coding mode of the block includes decoding at least one syntactic data element associated with the residual coding mode of the block of a picture, provided that transform skip is enabled. . A method for encoding,
obtaining a residual coding mode of a block of a picture, the residual coding mode being one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC); to obtain;
encoding the block of the picture according to the obtained residual coding mode;
encoding at least one syntactic data element associated with a residual coding mode of a block of a picture, provided that transform skip is enabled. An apparatus for encoding, comprising one or more processors, the one or more processors comprising:
obtaining a residual coding mode of a block of a picture, the residual coding mode being one of normal residual coding mode (RRC) or transform skip residual coding mode (TSRC); to obtain;
encoding the block of the picture according to the obtained residual coding mode;
and encoding at least one syntactic data element associated with a residual coding mode of a block of a picture, provided that transform skip is enabled. 8. The claim 5 or 7, wherein obtaining the residual coding mode further comprises setting the residual coding mode to normal residual coding mode (RRC) provided that transform skip is disabled. or the apparatus of claim 6 or 8. decoding at least one syntactic data element associated with enabling transform skipping for at least one region of a picture;
decoding the block of the picture according to the obtained residual coding mode when an intra subpartitioning type is set to no_split. 10. A method according to claim 1 or an apparatus according to any one of claims 6, 8 or 9. Further decoding at least one syntactic data element associated with enabling transform skip for at least one region of the picture when intra-subpartition (ISP) is enabled and transform skip is enabled. A method according to any one of claims 5, 7, 9 or 10, or an apparatus according to any one of claims 6, 8-10, comprising: decoding at least one syntactic data element associated with enabling transform skipping for at least one region of a picture;
decoding the block of the picture according to the obtained residual coding mode when transform skip is enabled for ISP and intra subpartition split type is set to no_split. 12. The method of claim 11, or the apparatus of claim 11. further comprising decoding the block of the picture according to the obtained residual coding mode when transform skip is enabled for ISP and an intra subpartition split type is set to no_split. 12. The method of claim 11 or the apparatus of claim 11. decoding at least one syntactic data element associated with a constraint enabling transform skip coding mode (TRskip);
decoding at least one syntactic data element associated with defining a constraint that enables a transform skip residual coding mode (TSRC) when the constraint enables a transform skip coding mode (TRskip); A method according to any one of claims 5, 7, 9-13, or an apparatus according to any one of claims 6, 8-13, further comprising: 14. The method of any one of claims 5, 7, 9-13, further comprising decoding at least one syntactic data element associated with defining a constraint enabling a transform skip residual coding mode (TSRC). or a device according to any one of claims 6, 8-13. 16. The method of claim 15, or claim 15, further comprising decoding at least one syntactic data element associated with defining a constraint to enable a transform skip residual coding mode (TSRC). device. further comprising decoding at least one syntactic data element associated with enabling transform skip residual coding for at least one region of the picture;
12. The obtaining of the residual coding mode further comprises decoding at least one syntax data element associated with a residual coding mode of a block of a picture when transform-skip residual coding is enabled. 17. The method of claim 16, or the apparatus of claim 16. When intra-subpartition (ISP) is enabled and transform skip is enabled, at least one high-level syntax element enabling transform skip for at least one region of the picture is signaled in the sequence parameter set (SPS) 12. The method of claim 11, or the apparatus of claim 11, wherein: 18. The method of claim 17, wherein the at least one syntactic data element associated with enabling transform skip residual coding of at least one region of a picture is signaled in the sequence parameter set (SPS). Or an apparatus according to claim 17. A non-transitory computer-readable medium containing data content generated according to the method of claim 7 or the apparatus of claim 8. For executing the decoding method according to any one of claims 5 or 9 to 19 or for executing the encoding method according to claim 7 when this program is executed on a computer A non-transitory computer-readable medium containing program code instructions for

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